Now that we know what you are looking for we can help with information, or advice.
1) Edward's date of birth in Ireland-civil registration of births in Ireland started in 1864 so there will be no birth certificate, Assuming for the moment he was also born c1830 it's also possible that no baptism record exists but to start looking for existing records you'd need to know both the family's religion and where they lived (parish of not actual townland).
You should, however, hopefully be able to narrow down when Edward was born by finding him in Scottish census records. Usually place of birth is 'Ireland' but you might be lucky and havbe the county listed (although is not enough information to locate church records)
2) marriage date and place-Since Margaret herself was born in Scotland (and Scottish records are available) that would be the logical place to start searching.
If you get the family in all avilable census records you should be able to narrow down the date a bit. However, Scottish birth certificates list date and place of parents' marriage - if any children are born in 1855 there's even more detail on those certificates.
Scotland's People website (
www.scotlandspeople.gov.uk) is the place for Scottish certificates and if you check the site it lists what's on Scottish birth, death and marriage certificates, etc.